Saddle block structure for excavators



Aug. 13, 1940. w. BAKER SADDLE BLOCK STRUCTURE FOR EXCAVATORS Filed June 28, 1939 s Sheets -Sheet 1 20 I qi ,0 35 /4 22 o DO /7 23 m /6 B 0 57 INVENTOR.

W4L 7 5/? 5 4 KER BY w A TTORNEY.

w. BAKER I 2,211,194

SADDLE BLOCK STRUCTURE FOR EXCAVATORS Aug. 13, 1940.

Filed June 28, 1939 3 Sheets-Sheet 2 \76 INVENTOR.

70 WALTER 54x54 ATTORNEY.

Aug. 13,1940. w. BAKER 2,211,194

' SADDLE BLOCK STRUCTURE FOR EXCAVA'I'ORS Filed June 28, 1939 3 Sheets-Sheet 3 INVEN TOR.

W/IL 75/? 64/057? ATTUP/VEX Patented Aug. 13, 1940 UNITED STATES earsur orrics SADDLE BLOCK STRUCTURE FOR EXCAVATORS Application June 28, 1939, Serial No. 281,540

6 Claims.

This invention relates to excavating shovels and has particular relation to means for compensating for wear in the saddle block, dipper stick, and crowding mechanism and parts thereof.

In the operation of excavation shovels and the like employing a dipper stick, considerable difficulty is encountered by reason of wear and friction which occurs in the means employed for slidably mounting the dipper stick in the saddle block of the boom, and in the mechanism employed for crowding or driving the dipper stick downwardly and outwardly while digging.

It is the usual practice to employ blocks or the like On which the dipper stick is slidably mounted. These blocks or wear plates, even though well greased, wear out rapidly and must be replaced. The excavating shovels frequently are used in excavating and moving materials such as quartz, coal, dry earth, sand and the like, particles of which materials may lodge on the dipper stick and wear plates and other moving parts of the saddle block and crowding mechanism to wear out and grind out the moving parts, and thus shorten their useful life.

The shovel manufacturers provide extra wear plates and extra parts for replacement purposes, but obviously such replacement is expensive and may take considerable time, which time may be needed in operating the shovel to maintain excavating schedules. Different metals have been tried out for the wear blocks and other parts, but no material increase in the effective life of the parts has been secured.

It is, therefore, one of the objects of my invention to overcome the difficulties above enumerated and to provide means for quickly and easily taking up wear in such parts of an excavating shovel as the means for engaging the dipper stick with the saddle block and the crowding mechamsm.

Another object of my invention is to provide a saddle block and dipper stick crowding structure which may be readily adjusted to compensate for wear to maintain these parts in substantially the same relation and at substantially the same clearances as when the shovel was new.

Still another object of my invention is to provide an improved dipper stick saddle block and crowding mechanism for excavating shovels.

Other and further featuresand objects of the invention will be more apparent to those skilled in the art upon a consideration of the accompanying drawings and following specifications, wherein are disclosed exemplary embodiments of (Cl. 214l35) the invention, with the understanding, however, that such changes may be made therein as fall within the scope of the appended claims, without departing from the spirit of the invention.

In said drawings:

Figure 1 is a view in perspective of an excavating shovel to which a saddle block, dipper stick and crowding structure, constructed according to one embodiment of my invention, has been applied.

Figure 2 is a view in perspective of one form of dipper stick mounting and crowding mechanism for use on the boom of the shovel shown in Figure 1.

Figure 3 is a view in front or end elevation of a complete saddle block constructed according to another embodiment of my invention as it appears when mounted on the boom of an excavating shovel. The boom is shown in section.

Figure 4 is a view in side elevation of the saddle block and boom shown in Figure 3, but with the crowding mechanism removed.

Figure 5 is a diagrammatic view illustrating how wear may be taken up in the dipper stick mounting and crowding mechanism.

Figure 6 is a view, partly in end elevation and partly in section, of a modified form of dipper stick actuating and supporting mechanism embodying my invention.

Figure 7 is a fragmentary View in side elevation and partly in section of a crowding mechanism utilizing a take-up device constructed in accordance with another embodiment of my invention, and

Figure 8 is a fragmentary view in elevation, partly broken away, to illustrate the application of adjusting means, constructed in accordance with my invention, to a square type boom and dipper stick and in which cable crowding means are employed.

Referring now to the drawings:

An excavating shovel to which my saddle block structure may be applied is illustrated in Figure 1. The excavating shovel here shown employs a lower or main frame I 0 on which sprocket wheels H are rotatably mounted. These wheels are driven by means of a sprocket l2 and chains l3 in accordance with the usual practice. Endless treads l 4 are mounted for rotation on the sprocket wheels at the front and rear of the main frame In. A bull ring I6 is mounted on the upper face of the lower frame Ill, and an upper frame H is mounted by means of rollers IS on the bull ring IS. The upper frame I! includes a turntable on which the rollers l8 are mounted.

A cab I9 is mounted on the upper frame I! and houses the driving motor (not shown) for raising and lowering the boom 25, for swinging the turntable and for driving the wheels I I, all in accordance with the usual practice. A short crowder chain 20 is also provided for applying power to the long crowder' chain 2| through sprockets 22 and 38 to effect crowding of the dipper stick 2?. Raising and lowering the boom 25 on its pivot or shaft 23 is accomplished by the cable 24, and swinging of the dipper stick 2! is accomplished by means of the cable 26, all in accordance with the usual practice.

The dipper stick 2! here shown includes two tubes 28 and 29. Gear racks 3| and 32 are mounted on the upper faces of the tubes 28 and 29 respectively. Stops such as that shown at 33 are employed on the extreme inner ends of the tubes of the dipper stick to prevent it from being driven too far outwardly by the crowding mechanism. The bucket or scoop 35 is mounted on the outer end of the dipper stick in accordance with standard practice.

The dipper stick may be crowded or driven outwardly with respect to the saddle block, indicated generally at 34, so that the teeth of the bucket will dig into the material being excavated. In the device here shown, crowding is effected by the operation of the chains 20 and 2 I. Pulling on the chain 24 rotates the sprocket 36 to rotate a shipper shaft 3? on which pinion gears 38 and 39 are mounted, The pinion gears 38 and 39 mesh with the teeth of the racks 3| and 32 and drive these racks and therefore the tubes 28 and 29 outwardly to effect crowding of the dipper stick and bucket. The long crowder chain 2! passes downwardly through the tubular boom 25 and around the sprocket 38 mounted on the pivotal axle of the boom. An adjustable idler sprocket 49 is mounted for free rotation near the lower end of the boom to take up any slack in the long crowder chain. I

The dipper stick crowding mechanism is mounted upon a saddle block 34 which is in turn bolted about the boom 25. The saddle block comprises in general a pair of castings 4! and 42, as shown in Figure 3. These castings are provided with semi-cylindrical recesses 43 and flanges as at 44 to permit the two sections to be placed around the boom 25 and be held in place by means of bolts 46.

The uppermost portion of each of the saddle members is' provided with a shelf or pedestal 41 and 48 on which pillow blocks 49 and 5! respectively may be mounted. It is in these pillow blocks that the shipper shaft 31 is rotatably mounted. As stated before, the operation of the crowder chain 2| serves to rotate the sprocket 36 and the shipper shaft 31 upon which it is mounted. This in turn rotates the pinion gears 38 and 39. v

It is necessary to support the racks 3| and 32 on the dipper stick in spaced relation to the shipper shaft and pinions to permit the pinions to drive the racks outwardly or inwardly without binding and regardless of the angular position of the dipper stick with respect to the boom. To this end I have provided the structure shown in detail in Figures 2 to 5 inclusive.

In the structure shown in Figure 2, triangular shaped hangers 52 and 53 are provided at each side of the saddle block. Each is provided near an upper corner with a bearing portion adapted to be received over the end of the shipper Shaft extending beyond the pinions. The remaining lower corners of the hangers are provided with openings in which short stub shafts 56 are mounted. These stub shafts are provided with shoulders 51 and threaded portions 58. Nuts 59 serve to clamp the stub shafts in position in their respective openings. Spool-like rollers 61 are mounted for free rotation on each of the stub shafts. The outer rolling surface of each roller is preferably curved as shown to permit the dipper stick tube members 28 and 29 to be supported thereon for rolling movement, while at the same time causing the rack on the upper side of each dipper stick tube to be held in engagement with the pinions. The curved or spool-like surfaces of the rollers prevent lateral displacement of the dipper stick with respect to the pinions.

The gears 38 and 39 really constitute rollers for the dipper stick and, in fact, if other forms of crowds are employed as for instance cable crowds rollers would be substituted for the gears. The gears 38 and 39 and the rollers 6| thus afford oppositely disposed rollers for supporting the dipper stick for in and out movement.

I have provided means for adjusting the center distances between the shipper shaft and the individual stub shafts s that this spacing can always be maintained at the most eificient and effective position. The journal portion 56a of each stub shaft is turned ccentric to the threaded portion 58. The threaded end of each stub shaft is provided with a squared or flattened portion 62 to permit the shaft to be turned to any desired position by means of a wrench. It is of course necessary to loosen the binding nut 59 on the shaft before it is rotated. The rotation of a stub shaft results in the eccentric portions thereof forcing its roller or spool member as tightly as desired against the lower surface of the dipper stick tube and permits adjustment as required.

In a modified form of the crowding mechanism illustrated in Figure 3, a pair of hangers 66 and 61 are provided at each end of the shipper shaft, one on either side of the pinion. This permits a light yet sturdy structure. The eccentric shafts for supporting the rollers are mounted between the lower ends of each pair of hangers, as shown in detail in Figure 5.

Each roller mounting shaft has portions of reduced diameter 68 and 69 near its ends adapted to be received in holes 79 extending through the hangers. The reduced portions of each shaft are provided with threads at the outer ends to permit the shaft to be clamped into position by means of nuts H and 72. The central larger portion of the shaft is turned eccentric to the smaller threaded portions of the shaft, the roller Bl being mounted for rotation upon the eccentric portion. The roller may of course be bushed if desired.

It is preferable that one end of the shaft be made to extend beyond the end of the clamping nut to permit its being flatted or squared, as at M. Thus the eccentric shaft may be rotated as required to take up any lost motion by simply loosening the lock nuts H and 72 and turning the shaft by means of a wrench applied to the squared portion 14 and again locking the looking nuts.

An opening is provided through the shaft as shown at 76 to permit lubricant to be forced through a fitting Tl onto the bearing surfaces of the rollers.

I have shown the eccentric shaft in Figure in the position to which it may be adjusted when considerable wear has taken place. The position of the roller when first installed is shown in dotted lines at 18.

I have provided means for readily and easily adjusting the crowding mechanism for the dipper stick of an excavating shovel. A crowding mechanism constructed in accordance with my invention makes it possible to maintain correct adjustment of the wearing parts without frequent replacement of parts. Furthermore, adjustment of the parts is possible without disassembling any of the structure. The shovel, therefore, need be out of service but a few minutes to make the adjustments for wear.

Various modifications of my invention may be made. For instance, the boom illustrated at 8! in Figure 6 may be square in cross section or open through the center, and the dipper stick 82 may be a single member instead of the two part member shown in Figure 1. Other crowding means may be employed, as for instance the cable crowds 85 shown in Figure 8, in which case rollers 61 would be used instead of the gears 38 and 39. Obviously, too, the positions of the rollers and crowding drive could be reversed as shown in Figure 8 with the take up for wear located above the horizontal plane of the axis of the dipper stick and the crowding mechanism below. The take up may be in the shipper shaft as shown in Figure '7 rather than in the rollers, in which case the shipper shaft 88 may be rotatably mounted in an eccentric bushing 89 having flattened sides, as at 95, to permit adjustment with a wrench. The principles involved are the substitution of rolling friction for sliding friction and the taking up or adjustment for wear by decreasing the spacing between th opposed rollers which support the dipper stick. Friction and wear are thus minimized and dead thrust of the gears largely eliminated.

Although I have described several specific embodiments of my invention, it is apparent that modifications thereof may be made by those skilled in the art. Such modifications may be made without departing from the spirit and scope of my invention as set forth in the appended claims.

I claim:

1. In an excavating shovel, a boom, a saddle block mounted on the boom, a shipper shaft on the saddle block, a dipper stick, a gear rack on the dipper stick, a gear on the shipper shaft to drive the gear rack and thus the dipper stick in and out, and means for supporting the dipper stick on the side opposite to the gear and gear rack comprising at least one roller, said roller being provided with a rotatable off-center shaft so that the roller may be adjusted with reference to the gear to compensate for wear in the roller and aforesaid parts.

2. In an excavating shovel, a boom, a saddle block, a two-part dipper stick with the parts thereof on opposite sides of the boom, a shipper shaft rotatably mounted on the saddle block, gears on the opposite ends of the shipper shaft, a gear rack on each part of the dipper stick positioned to engage the gears of the shipper shaft, hangers mounted on the opposite ends of the shipper shaft for rotation with respect thereto, said hangers having rotatably mounted off-center shafts, and rollers mounted on the off-center shafts positioned to engage the faces of the dipper sticks opposite to the gear racks to thereby provide with the gears a rolling mounting for the two parts of the dipper stick to thereby minimize wear, and the rollers on the off-center shafts being adjustable so that the spacing of the rollers with reference to the gears may be varied to take up wear in the parts of the dipper stick and its driving mechanism.

3. In a dipper stick crowding mechanism, a boom, a shipper shaft, a means for rotatably supporting the shipper shaft in a lateral position relative to the boom, a means for driving the shipper shaft, pinions on the shipper shaft, racks on the dipper stick to engage with the pinions, hangers pivotally mounted upon the shipper shaft, means mounted on the hangers for supporting the dipper stick in spaced relation to the pinions, said means including rollers, shafts for supporting the rollers for rotation, and means for clamping the shafts to the hangers, and roller supporting portion of the shafts and the clamping portion of the shafts being formed eccentric to permit raising or lowering of the rollers.

4. In a crowding mechanism of the class described, having hangers for supporting a dipper stick, a roller for engaging the dipper stick, a shaft for rotatably mounting the roller, means for mounting the last mentioned shaft including a shoulder on the shaft, a threaded portion of the shaft adjacent the shoulder mounted in a hole extending through one end of a hanger, a nut to clamp the shaft in position, the portion of the shaft on which the roller is mounted being made eccentric to the threaded portion of the shaft, and means on the shaft for use in turning the shaft to secure adjustment of the roller.

5. In an excavating shovel, a boom, a dipper stick, and means for supporting the dipper stick for in and out movement including a shipper shaft, hangers mounted for rotation on the shipper shaft and shafts clamped to the hangers having rollers for engaging the dipper stick, the portions of the shafts on which the rollers are mounted being eccentric to the portion clamped to the hangers to permit adjustment of the rollers to take up wear.

6. In an excavating shovel, a boom, a dipper stick, and means for mounting the dipper stick for reciprocating movement on the boom, including a pair of hangers on opposite sides of the dipper stick, shafts joining the hangers and forming with the hangers an enclosure surrounding the dipper stick, rollers on the shafts for engag ing the dipper stick, at least one of the shafts having an eccentric middle portion on which its roller is mounted, and the shaft having clamping means to clamp the shaft against the hangers to form a spacer for the hangers and to provide an adjustable eccentric roller to take up wear.

WALTER BAKER. 

